A wind park can comprise any number of wind turbines for generating electrical power and feeding this into an electrical grid. Usually, the operator of a wind park must ensure that the wind park is operated according to the applicable regulations or grid code. The grid code can define various aspects of the performance of the wind park, for example the reaction to a fault on the grid side or wind park side. There are various types of fault, and the wind park must be able to respond reliably and quickly in each case in order to avoid sanctions in case of non-compliance. For example, the wind park must be able to respond to a low-voltage or overvoltage event. Such an event can happen at any time as a result of an instability or fault in the electrical grid. In prior art solutions, a wind turbine may be equipped with a circuit breaker that trips during an excessively high grid-side voltage, in order to disconnect the wind turbine with the aim of avoiding damage to the wind turbine components. However, disconnection and subsequent re-connection of the wind turbine generator effectively prolong the instability of the grid. Therefore, newer grid codes may stipulate that the wind turbines of a wind park remain connected during an overvoltage event in order to be able to support the grid to resume normal operation as quickly as possible. To deal with this requirement, it has been proposed to equip each wind turbine with a full-scale power converter that is capable of absorbing reactive power. During an overvoltage event, such power converters absorb reactive power and effectively act to “pull down” the voltage, while protecting the wind turbine. For example, if such a power converter is already producing reactive power when an overvoltage event occurs, it will stop producing reactive power and start absorbing it instead. To this end, a suitable controller is required to control the operation of the power converter. However, equipping each wind turbine with such an additional expensive component significantly adds to the overall cost of a wind park. Furthermore, for reliable overvoltage response at all times, the power converter must be realised to absorb a maximum reactive power level, for example when an overvoltage event occurs while the wind turbine is operating at full rated output.